Originally published on January 16th, 2013 at dailynews.com.By Stephanie Cary-------A sign reading "Thank you for not smoking" hung on the front door of her home for years.

Neither Carollee Stater nor her husband ever smoked cigarettes, and the sign was to prevent secondhand smoke from visitors at her Apple Valley home.

But her efforts didn't stop the 73-year-old from being diagnosed with advanced lung cancer almost seven years ago.

"Unless you tell them up front that you've never smoked, the first question people ask is how long did you smoke?" Stater says. "That's fairly typical. People just assume that you got it because you smoked."

And the stigma is not exclusive to Stater. The Lung Cancer Project - a research collaboration aimed at better understanding lung cancer biases - found that three out of four people had a negative bias toward people with lung cancer.

"We found that people had conscious and unconscious beliefs that were more negative toward lung cancer and people suffering from the disease as compared to people with breast cancer," says Brian Nosek, founder of Project Implicit, a multi-university research collaboration involved in The Lung Cancer Project.

"For example, we found that people perceived those with lung cancer to be more to blame for their cancer, and that their diagnosis was more hopeless. This is probably due to the fact of the well-known association between smoking and lung cancer."

And while these are only the initial findings of the ongoing study, Dr. Marianna

Koczywas, an oncologist at the City of Hope who treats Stater along with many other lung cancer patients, says she has seen the negative connotation lung cancer patients, their families and the public associate with the diagnosis.Many of her patients who were smokers, or had family members who smoked, say they deserve the disease because of the habit, she says.

And even those who didn't smoke are still assumed to have done so, she says.

While it's true that smoking is a main cause of lung cancer - active smoking attributes to almost 90 percent of lung cancer patients, according to the American Lung Association - Koczywas says a growing number of patients diagnosed with the disease never smoked.

"So I think that the thought has been changing," Koczywas says. "And I think from a physician's point of view, we're taught to educate these patients, their families and society that not everyone who develops lung cancer has cigarette exposure."

Other causes of lung cancer include exposure to asbestos, radiation or toxic chemicals like radon, and medical conditions that cause recurrent lung inflammation or lung scarring from diseases such as tuberculosis, says Koczywas.

In fact, radon exposure is the second-leading cause of lung cancer, accounting for 15,000 to 22,000 lung cancer deaths each year, according to the American Lung Association.

Stater, who never smoked and tried to avoid being around secondhand smoke, couldn't believe her diagnosis.

"I thought this is impossible, it shouldn't be happening to me," Stater says.

She still can't put a finger on the possible cause of her diagnosis, but Koczywas says patients shouldn't dwell on the reason why they got the cancer, but rather focus on the future and beating the disease.

Nosek hopes The Lung Cancer Project will help not only reduce the stigma associated with the disease, but also raise awareness of the other causes of lung cancer and promote treatment seeking.

"Effective treatment is not just knowing what procedure to do or medicine to give. It also includes proper preventative care, treatment seeking, and many other behaviors that relate to people's beliefs about what they think they can do and their knowledge about their health and diseases," Nosek says.

"Better knowledge will lead to better care," he adds.

As for Stater, she just wants people to not assume that she, or other people with the disease, were smokers and deserve their diagnosis.

"Even having a smoker in the house doesn't mean that you got it because of that," Stater says. "You could have picked it up anywhere, any party you've gone to, just the right amount of whatever to trigger the cancer. You just never know."